Abstract

The cultivation of proteas for cut-flowers is a thriving industry in Australia and especially Western Australia. However, proteas are susceptible to a ‘sudden death’ syndrome and this has large economic consequences for the industry. Protea plantations in the south-west of Western Australia were assessed during 1999 to 2001 to determine the causes of Sudden Death. Phytophthora cinnamomi was isolated from the stems and roots of dying plants at 11 of the 28 plantations sampled. These included plants from four genera, Leucadendron, Leucospermum, Protea and Serruria. Protea death and decline was also attributed to other fungal pathogens, a range of pests, nutritional disorders and physical factors. The interaction of these factors will be discussed.